packages/flutter/test/material/floating_action_button_location_test.dart - mirrors/flutter - Git at Google

 // Copyright 2018 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:math';

 import 'package:flutter/foundation.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter_test/flutter_test.dart';

 void main() {
   group('Basic floating action button locations', () {
     testWidgets('still animates motion when the floating action button is null', (WidgetTester tester) async {
       await tester.pumpWidget(buildFrame(fab: null, location: null));

       expect(find.byType(FloatingActionButton), findsNothing);
       expect(tester.binding.transientCallbackCount, 0);

       await tester.pumpWidget(buildFrame(fab: null, location: FloatingActionButtonLocation.endFloat));

       expect(find.byType(FloatingActionButton), findsNothing);
       expect(tester.binding.transientCallbackCount, greaterThan(0));

       await tester.pumpWidget(buildFrame(fab: null, location: FloatingActionButtonLocation.centerFloat));

       expect(find.byType(FloatingActionButton), findsNothing);
       expect(tester.binding.transientCallbackCount, greaterThan(0));
     });

     testWidgets('moves fab from center to end and back', (WidgetTester tester) async {
       await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat));

       expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 356.0));
       expect(tester.binding.transientCallbackCount, 0);

       await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat));

       expect(tester.binding.transientCallbackCount, greaterThan(0));

       await tester.pumpAndSettle();

       expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(400.0, 356.0));
       expect(tester.binding.transientCallbackCount, 0);

       await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat));

       expect(tester.binding.transientCallbackCount, greaterThan(0));

       await tester.pumpAndSettle();

       expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 356.0));
       expect(tester.binding.transientCallbackCount, 0);
     });

     testWidgets('moves to and from custom-defined positions', (WidgetTester tester) async {
       await tester.pumpWidget(buildFrame(location: const _StartTopFloatingActionButtonLocation()));

       expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(44.0, 56.0));

       await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat));
       expect(tester.binding.transientCallbackCount, greaterThan(0));

       await tester.pumpAndSettle();

       expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(400.0, 356.0));
       expect(tester.binding.transientCallbackCount, 0);

       await tester.pumpWidget(buildFrame(location: const _StartTopFloatingActionButtonLocation()));

       expect(tester.binding.transientCallbackCount, greaterThan(0));

       await tester.pumpAndSettle();

       expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(44.0, 56.0));
       expect(tester.binding.transientCallbackCount, 0);

     });

     group('interrupts in-progress animations without jumps', () {
       _GeometryListener geometryListener;
       ScaffoldGeometry geometry;
       _GeometryListenerState listenerState;
       Size previousRect;
       Iterable<double> previousRotations;

       // The maximum amounts we expect the fab width and height to change
       // during one step of a transition.
       const double maxDeltaWidth = 12.5;
       const double maxDeltaHeight = 12.5;

       // The maximum amounts we expect the fab icon to rotate during one step
       // of a transition.
       const double maxDeltaRotation = 0.09;

       // We'll listen to the Scaffold's geometry for any 'jumps' to detect
       // changes in the size and rotation of the fab.
       void setupListener(WidgetTester tester) {
         // Measure the delta in width and height of the fab, and check that it never grows
         // by more than the expected maximum deltas.
         void check() {
           geometry = listenerState.cache.value;
           final Size currentRect = geometry.floatingActionButtonArea?.size;
           // Measure the delta in width and height of the rect, and check that
           // it never grows by more than a safe amount.
           if (previousRect != null && currentRect != null) {
             final double deltaWidth = currentRect.width - previousRect.width;
             final double deltaHeight = currentRect.height - previousRect.height;
             expect(
               deltaWidth.abs(),
               lessThanOrEqualTo(maxDeltaWidth),
               reason: "The Floating Action Button's width should not change "
                   'faster than $maxDeltaWidth per animation step.\n'
                   'Prevous rect: $previousRect, current rect: $currentRect',
             );
             expect(
               deltaHeight.abs(),
               lessThanOrEqualTo(maxDeltaHeight),
               reason: "The Floating Action Button's width should not change "
                   'faster than $maxDeltaHeight per animation step.\n'
                   'Prevous rect: $previousRect, current rect: $currentRect',
             );
           }
           previousRect = currentRect;

           // Measure the delta in rotation.
           // Check that it never grows by more than a safe amount.
           //
           // Note that there may be multiple transitions all active at
           // the same time. We are concerned only with the closest one.
           final Iterable<RotationTransition> rotationTransitions = tester.widgetList(
             find.byType(RotationTransition),
           );
           final Iterable<double> currentRotations = rotationTransitions.map(
               (RotationTransition t) => t.turns.value);

           if (previousRotations != null && previousRotations.isNotEmpty
               && currentRotations != null && currentRotations.isNotEmpty
               && previousRect != null && currentRect != null) {
             final List<double> deltas = <double>[];
             for (double currentRotation in currentRotations) {
               double minDelta;
               for (double previousRotation in previousRotations) {
                 final double delta = (previousRotation - currentRotation).abs();
                 minDelta ??= delta;
                 minDelta = min(delta, minDelta);
               }
               deltas.add(minDelta);
             }

             if (deltas.where((double delta) => delta < maxDeltaRotation).isEmpty) {
               fail("The Floating Action Button's rotation should not change "
                   'faster than $maxDeltaRotation per animation step.\n'
                   'Detected deltas were: $deltas\n'
                   'Previous values: $previousRotations, current values: $currentRotations\n'
                   'Prevous rect: $previousRect, current rect: $currentRect',);
             }
           }
           previousRotations = currentRotations;
         }

         listenerState = tester.state(find.byType(_GeometryListener));
         listenerState.geometryListenable.addListener(check);
       }

       setUp(() {
         // We create the geometry listener here, but it can only be set up
         // after it is pumped into the widget tree and a tester is
         // available.
         geometryListener = _GeometryListener();
         geometry = null;
         listenerState = null;
         previousRect = null;
         previousRotations = null;
       });

       testWidgets('moving the fab to centerFloat', (WidgetTester tester) async {
         // Create a scaffold with the fab at endFloat
         await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat, listener: geometryListener));
         setupListener(tester);

         // Move the fab to centerFloat'
         await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat, listener: geometryListener));
         await tester.pumpAndSettle();
       });

       testWidgets('interrupting motion towards the StartTop location.', (WidgetTester tester) async {
         await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat, listener: geometryListener));
         setupListener(tester);

         // Move the fab to the top start after creating the fab.
         await tester.pumpWidget(buildFrame(location: const _StartTopFloatingActionButtonLocation(), listener: geometryListener));
         await tester.pump(kFloatingActionButtonSegue ~/ 2);

         // Interrupt motion to move to the end float
         await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat, listener: geometryListener));
         await tester.pumpAndSettle();
       });

       testWidgets('interrupting entrance to remove the fab.', (WidgetTester tester) async {
         await tester.pumpWidget(buildFrame(fab: null, location: FloatingActionButtonLocation.centerFloat, listener: geometryListener));
         setupListener(tester);

         // Animate the fab in.
         await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat, listener: geometryListener));
         await tester.pump(kFloatingActionButtonSegue ~/ 2);

         // Remove the fab.
         await tester.pumpWidget(
           buildFrame(
             fab: null,
             location: FloatingActionButtonLocation.endFloat,
             listener: geometryListener,
           ),
         );
         await tester.pumpAndSettle();
       });

       testWidgets('interrupting entrance of a new fab.', (WidgetTester tester) async {
         await tester.pumpWidget(
           buildFrame(
             fab: null,
             location: FloatingActionButtonLocation.endFloat,
             listener: geometryListener,
           ),
         );
         setupListener(tester);

         // Bring in a new fab.
         await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat, listener: geometryListener));
         await tester.pump(kFloatingActionButtonSegue ~/ 2);

         // Interrupt motion to move the fab.
         await tester.pumpWidget(
           buildFrame(
             location: FloatingActionButtonLocation.endFloat,
             listener: geometryListener,
           ),
         );
         await tester.pumpAndSettle();
       });
     });
   });

   testWidgets('Docked floating action button locations', (WidgetTester tester) async {
     await tester.pumpWidget(
       buildFrame(
         location: FloatingActionButtonLocation.endDocked,
         bab: const SizedBox(height: 100.0),
         viewInsets: EdgeInsets.zero,
       ),
     );

     // Scaffold 800x600, FAB is 56x56, BAB is 800x100, FAB's center is
     // at the top of the BAB.
     expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 500.0));

     await tester.pumpWidget(
       buildFrame(
         location: FloatingActionButtonLocation.centerDocked,
         bab: const SizedBox(height: 100.0),
         viewInsets: EdgeInsets.zero,
       ),
     );
     await tester.pumpAndSettle();
     expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(400.0, 500.0));


     await tester.pumpWidget(
       buildFrame(
         location: FloatingActionButtonLocation.endDocked,
         bab: const SizedBox(height: 100.0),
         viewInsets: EdgeInsets.zero,
       ),
     );
     await tester.pumpAndSettle();
     expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 500.0));
   });

   testWidgets('Docked floating action button locations: no BAB, small BAB', (WidgetTester tester) async {
     await tester.pumpWidget(
       buildFrame(
         location: FloatingActionButtonLocation.endDocked,
         viewInsets: EdgeInsets.zero,
       ),
     );
     expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 572.0));

     await tester.pumpWidget(
       buildFrame(
         location: FloatingActionButtonLocation.endDocked,
         bab: const SizedBox(height: 16.0),
         viewInsets: EdgeInsets.zero,
       ),
     );
     expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 572.0));
   });

   testWidgets('Mini-start-top floating action button location', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
         home: Scaffold(
           appBar: AppBar(),
           floatingActionButton: FloatingActionButton(onPressed: () { }, mini: true),
           floatingActionButtonLocation: FloatingActionButtonLocation.miniStartTop,
           body: Column(
             children: const <Widget>[
               ListTile(
                 leading: CircleAvatar(),
               ),
             ],
           ),
         ),
       ),
     );
     expect(tester.getCenter(find.byType(FloatingActionButton)).dx, tester.getCenter(find.byType(CircleAvatar)).dx);
     expect(tester.getCenter(find.byType(FloatingActionButton)).dy, kToolbarHeight);
   });

   testWidgets('Start-top floating action button location LTR', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
         home: Scaffold(
           appBar: AppBar(),
           floatingActionButton: const FloatingActionButton(onPressed: null),
           floatingActionButtonLocation: FloatingActionButtonLocation.startTop,
         ),
       ),
     );
     expect(tester.getRect(find.byType(FloatingActionButton)), Rect.fromLTWH(16.0, 28.0, 56.0, 56.0));
   });

   testWidgets('End-top floating action button location RTL', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
         home: Directionality(
           textDirection: TextDirection.rtl,
           child: Scaffold(
             appBar: AppBar(),
             floatingActionButton: const FloatingActionButton(onPressed: null),
             floatingActionButtonLocation: FloatingActionButtonLocation.endTop,
           ),
         ),
       ),
     );
     expect(tester.getRect(find.byType(FloatingActionButton)), Rect.fromLTWH(16.0, 28.0, 56.0, 56.0));
   });

   testWidgets('Start-top floating action button location RTL', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
         home: Directionality(
           textDirection: TextDirection.rtl,
           child: Scaffold(
             appBar: AppBar(),
             floatingActionButton: const FloatingActionButton(onPressed: null),
             floatingActionButtonLocation: FloatingActionButtonLocation.startTop,
           ),
         ),
       ),
     );
     expect(tester.getRect(find.byType(FloatingActionButton)), Rect.fromLTWH(800.0 - 56.0 - 16.0, 28.0, 56.0, 56.0));
   });

   testWidgets('End-top floating action button location LTR', (WidgetTester tester) async {
     await tester.pumpWidget(
       MaterialApp(
         home: Scaffold(
           appBar: AppBar(),
           floatingActionButton: const FloatingActionButton(onPressed: null),
           floatingActionButtonLocation: FloatingActionButtonLocation.endTop,
         ),
       ),
     );
     expect(tester.getRect(find.byType(FloatingActionButton)), Rect.fromLTWH(800.0 - 56.0 - 16.0, 28.0, 56.0, 56.0));
   });
 }


 class _GeometryListener extends StatefulWidget {
   @override
   State createState() => _GeometryListenerState();
 }

 class _GeometryListenerState extends State<_GeometryListener> {
   @override
   Widget build(BuildContext context) {
     return CustomPaint(
       painter: cache
     );
   }

   int numNotifications = 0;
   ValueListenable<ScaffoldGeometry> geometryListenable;
   _GeometryCachePainter cache;

   @override
   void didChangeDependencies() {
     super.didChangeDependencies();
     final ValueListenable<ScaffoldGeometry> newListenable = Scaffold.geometryOf(context);
     if (geometryListenable == newListenable)
       return;

     if (geometryListenable != null)
       geometryListenable.removeListener(onGeometryChanged);

     geometryListenable = newListenable;
     geometryListenable.addListener(onGeometryChanged);
     cache = _GeometryCachePainter(geometryListenable);
   }

   void onGeometryChanged() {
     numNotifications += 1;
   }
 }


 // The Scaffold.geometryOf() value is only available at paint time.
 // To fetch it for the tests we implement this CustomPainter that just
 // caches the ScaffoldGeometry value in its paint method.
 class _GeometryCachePainter extends CustomPainter {
   _GeometryCachePainter(this.geometryListenable) : super(repaint: geometryListenable);

   final ValueListenable<ScaffoldGeometry> geometryListenable;

   ScaffoldGeometry value;
   @override
   void paint(Canvas canvas, Size size) {
     value = geometryListenable.value;
   }

   @override
   bool shouldRepaint(_GeometryCachePainter oldDelegate) {
     return true;
   }
 }

 Widget buildFrame({
   FloatingActionButton fab = const FloatingActionButton(
     onPressed: null,
     child: Text('1'),
   ),
   FloatingActionButtonLocation location,
   _GeometryListener listener,
   TextDirection textDirection = TextDirection.ltr,
   EdgeInsets viewInsets = const EdgeInsets.only(bottom: 200.0),
   Widget bab,
 }) {
   return Localizations(
     locale: const Locale('en', 'us'),
     delegates: const <LocalizationsDelegate<dynamic>>[
       DefaultWidgetsLocalizations.delegate,
       DefaultMaterialLocalizations.delegate,
     ],
     child: Directionality(
     textDirection: textDirection,
     child: MediaQuery(
       data: MediaQueryData(viewInsets: viewInsets),
       child: Scaffold(
         appBar: AppBar(title: const Text('FabLocation Test')),
         floatingActionButtonLocation: location,
         floatingActionButton: fab,
         bottomNavigationBar: bab,
         body: listener,
       ),
     ),
   ));
 }

 class _StartTopFloatingActionButtonLocation extends FloatingActionButtonLocation {
   const _StartTopFloatingActionButtonLocation();

   @override
   Offset getOffset(ScaffoldPrelayoutGeometry scaffoldGeometry) {
     double fabX;
     assert(scaffoldGeometry.textDirection != null);
     switch (scaffoldGeometry.textDirection) {
       case TextDirection.rtl:
         final double startPadding = kFloatingActionButtonMargin + scaffoldGeometry.minInsets.right;
         fabX = scaffoldGeometry.scaffoldSize.width - scaffoldGeometry.floatingActionButtonSize.width - startPadding;
         break;
       case TextDirection.ltr:
         final double startPadding = kFloatingActionButtonMargin + scaffoldGeometry.minInsets.left;
         fabX = startPadding;
         break;
     }
     final double fabY = scaffoldGeometry.contentTop - (scaffoldGeometry.floatingActionButtonSize.height / 2.0);
     return Offset(fabX, fabY);
   }
 }
	// Copyright 2018 The Chromium Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:math';

	import 'package:flutter/foundation.dart';
	import 'package:flutter/material.dart';
	import 'package:flutter_test/flutter_test.dart';

	void main() {
	group('Basic floating action button locations', () {
	testWidgets('still animates motion when the floating action button is null', (WidgetTester tester) async {
	await tester.pumpWidget(buildFrame(fab: null, location: null));

	expect(find.byType(FloatingActionButton), findsNothing);
	expect(tester.binding.transientCallbackCount, 0);

	await tester.pumpWidget(buildFrame(fab: null, location: FloatingActionButtonLocation.endFloat));

	expect(find.byType(FloatingActionButton), findsNothing);
	expect(tester.binding.transientCallbackCount, greaterThan(0));

	await tester.pumpWidget(buildFrame(fab: null, location: FloatingActionButtonLocation.centerFloat));

	expect(find.byType(FloatingActionButton), findsNothing);
	expect(tester.binding.transientCallbackCount, greaterThan(0));
	});

	testWidgets('moves fab from center to end and back', (WidgetTester tester) async {
	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat));

	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 356.0));
	expect(tester.binding.transientCallbackCount, 0);

	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat));

	expect(tester.binding.transientCallbackCount, greaterThan(0));

	await tester.pumpAndSettle();

	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(400.0, 356.0));
	expect(tester.binding.transientCallbackCount, 0);

	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat));

	expect(tester.binding.transientCallbackCount, greaterThan(0));

	await tester.pumpAndSettle();

	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 356.0));
	expect(tester.binding.transientCallbackCount, 0);
	});

	testWidgets('moves to and from custom-defined positions', (WidgetTester tester) async {
	await tester.pumpWidget(buildFrame(location: const _StartTopFloatingActionButtonLocation()));

	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(44.0, 56.0));

	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat));
	expect(tester.binding.transientCallbackCount, greaterThan(0));

	await tester.pumpAndSettle();

	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(400.0, 356.0));
	expect(tester.binding.transientCallbackCount, 0);

	await tester.pumpWidget(buildFrame(location: const _StartTopFloatingActionButtonLocation()));

	expect(tester.binding.transientCallbackCount, greaterThan(0));

	await tester.pumpAndSettle();

	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(44.0, 56.0));
	expect(tester.binding.transientCallbackCount, 0);

	});

	group('interrupts in-progress animations without jumps', () {
	_GeometryListener geometryListener;
	ScaffoldGeometry geometry;
	_GeometryListenerState listenerState;
	Size previousRect;
	Iterable<double> previousRotations;

	// The maximum amounts we expect the fab width and height to change
	// during one step of a transition.
	const double maxDeltaWidth = 12.5;
	const double maxDeltaHeight = 12.5;

	// The maximum amounts we expect the fab icon to rotate during one step
	// of a transition.
	const double maxDeltaRotation = 0.09;

	// We'll listen to the Scaffold's geometry for any 'jumps' to detect
	// changes in the size and rotation of the fab.
	void setupListener(WidgetTester tester) {
	// Measure the delta in width and height of the fab, and check that it never grows
	// by more than the expected maximum deltas.
	void check() {
	geometry = listenerState.cache.value;
	final Size currentRect = geometry.floatingActionButtonArea?.size;
	// Measure the delta in width and height of the rect, and check that
	// it never grows by more than a safe amount.
	if (previousRect != null && currentRect != null) {
	final double deltaWidth = currentRect.width - previousRect.width;
	final double deltaHeight = currentRect.height - previousRect.height;
	expect(
	deltaWidth.abs(),
	lessThanOrEqualTo(maxDeltaWidth),
	reason: "The Floating Action Button's width should not change "
	'faster than $maxDeltaWidth per animation step.\n'
	'Prevous rect: $previousRect, current rect: $currentRect',
	);
	expect(
	deltaHeight.abs(),
	lessThanOrEqualTo(maxDeltaHeight),
	reason: "The Floating Action Button's width should not change "
	'faster than $maxDeltaHeight per animation step.\n'
	'Prevous rect: $previousRect, current rect: $currentRect',
	);
	}
	previousRect = currentRect;

	// Measure the delta in rotation.
	// Check that it never grows by more than a safe amount.
	//
	// Note that there may be multiple transitions all active at
	// the same time. We are concerned only with the closest one.
	final Iterable<RotationTransition> rotationTransitions = tester.widgetList(
	find.byType(RotationTransition),
	);
	final Iterable<double> currentRotations = rotationTransitions.map(
	(RotationTransition t) => t.turns.value);

	if (previousRotations != null && previousRotations.isNotEmpty
	&& currentRotations != null && currentRotations.isNotEmpty
	&& previousRect != null && currentRect != null) {
	final List<double> deltas = <double>[];
	for (double currentRotation in currentRotations) {
	double minDelta;
	for (double previousRotation in previousRotations) {
	final double delta = (previousRotation - currentRotation).abs();
	minDelta ??= delta;
	minDelta = min(delta, minDelta);
	}
	deltas.add(minDelta);
	}

	if (deltas.where((double delta) => delta < maxDeltaRotation).isEmpty) {
	fail("The Floating Action Button's rotation should not change "
	'faster than $maxDeltaRotation per animation step.\n'
	'Detected deltas were: $deltas\n'
	'Previous values: $previousRotations, current values: $currentRotations\n'
	'Prevous rect: $previousRect, current rect: $currentRect',);
	}
	}
	previousRotations = currentRotations;
	}

	listenerState = tester.state(find.byType(_GeometryListener));
	listenerState.geometryListenable.addListener(check);
	}

	setUp(() {
	// We create the geometry listener here, but it can only be set up
	// after it is pumped into the widget tree and a tester is
	// available.
	geometryListener = _GeometryListener();
	geometry = null;
	listenerState = null;
	previousRect = null;
	previousRotations = null;
	});

	testWidgets('moving the fab to centerFloat', (WidgetTester tester) async {
	// Create a scaffold with the fab at endFloat
	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat, listener: geometryListener));
	setupListener(tester);

	// Move the fab to centerFloat'
	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat, listener: geometryListener));
	await tester.pumpAndSettle();
	});

	testWidgets('interrupting motion towards the StartTop location.', (WidgetTester tester) async {
	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat, listener: geometryListener));
	setupListener(tester);

	// Move the fab to the top start after creating the fab.
	await tester.pumpWidget(buildFrame(location: const _StartTopFloatingActionButtonLocation(), listener: geometryListener));
	await tester.pump(kFloatingActionButtonSegue ~/ 2);

	// Interrupt motion to move to the end float
	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat, listener: geometryListener));
	await tester.pumpAndSettle();
	});

	testWidgets('interrupting entrance to remove the fab.', (WidgetTester tester) async {
	await tester.pumpWidget(buildFrame(fab: null, location: FloatingActionButtonLocation.centerFloat, listener: geometryListener));
	setupListener(tester);

	// Animate the fab in.
	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.endFloat, listener: geometryListener));
	await tester.pump(kFloatingActionButtonSegue ~/ 2);

	// Remove the fab.
	await tester.pumpWidget(
	buildFrame(
	fab: null,
	location: FloatingActionButtonLocation.endFloat,
	listener: geometryListener,
	),
	);
	await tester.pumpAndSettle();
	});

	testWidgets('interrupting entrance of a new fab.', (WidgetTester tester) async {
	await tester.pumpWidget(
	buildFrame(
	fab: null,
	location: FloatingActionButtonLocation.endFloat,
	listener: geometryListener,
	),
	);
	setupListener(tester);

	// Bring in a new fab.
	await tester.pumpWidget(buildFrame(location: FloatingActionButtonLocation.centerFloat, listener: geometryListener));
	await tester.pump(kFloatingActionButtonSegue ~/ 2);

	// Interrupt motion to move the fab.
	await tester.pumpWidget(
	buildFrame(
	location: FloatingActionButtonLocation.endFloat,
	listener: geometryListener,
	),
	);
	await tester.pumpAndSettle();
	});
	});
	});

	testWidgets('Docked floating action button locations', (WidgetTester tester) async {
	await tester.pumpWidget(
	buildFrame(
	location: FloatingActionButtonLocation.endDocked,
	bab: const SizedBox(height: 100.0),
	viewInsets: EdgeInsets.zero,
	),
	);

	// Scaffold 800x600, FAB is 56x56, BAB is 800x100, FAB's center is
	// at the top of the BAB.
	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 500.0));

	await tester.pumpWidget(
	buildFrame(
	location: FloatingActionButtonLocation.centerDocked,
	bab: const SizedBox(height: 100.0),
	viewInsets: EdgeInsets.zero,
	),
	);
	await tester.pumpAndSettle();
	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(400.0, 500.0));


	await tester.pumpWidget(
	buildFrame(
	location: FloatingActionButtonLocation.endDocked,
	bab: const SizedBox(height: 100.0),
	viewInsets: EdgeInsets.zero,
	),
	);
	await tester.pumpAndSettle();
	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 500.0));
	});

	testWidgets('Docked floating action button locations: no BAB, small BAB', (WidgetTester tester) async {
	await tester.pumpWidget(
	buildFrame(
	location: FloatingActionButtonLocation.endDocked,
	viewInsets: EdgeInsets.zero,
	),
	);
	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 572.0));

	await tester.pumpWidget(
	buildFrame(
	location: FloatingActionButtonLocation.endDocked,
	bab: const SizedBox(height: 16.0),
	viewInsets: EdgeInsets.zero,
	),
	);
	expect(tester.getCenter(find.byType(FloatingActionButton)), const Offset(756.0, 572.0));
	});

	testWidgets('Mini-start-top floating action button location', (WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	appBar: AppBar(),
	floatingActionButton: FloatingActionButton(onPressed: () { }, mini: true),
	floatingActionButtonLocation: FloatingActionButtonLocation.miniStartTop,
	body: Column(
	children: const <Widget>[
	ListTile(
	leading: CircleAvatar(),
	),
	],
	),
	),
	),
	);
	expect(tester.getCenter(find.byType(FloatingActionButton)).dx, tester.getCenter(find.byType(CircleAvatar)).dx);
	expect(tester.getCenter(find.byType(FloatingActionButton)).dy, kToolbarHeight);
	});

	testWidgets('Start-top floating action button location LTR', (WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	appBar: AppBar(),
	floatingActionButton: const FloatingActionButton(onPressed: null),
	floatingActionButtonLocation: FloatingActionButtonLocation.startTop,
	),
	),
	);
	expect(tester.getRect(find.byType(FloatingActionButton)), Rect.fromLTWH(16.0, 28.0, 56.0, 56.0));
	});

	testWidgets('End-top floating action button location RTL', (WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Directionality(
	textDirection: TextDirection.rtl,
	child: Scaffold(
	appBar: AppBar(),
	floatingActionButton: const FloatingActionButton(onPressed: null),
	floatingActionButtonLocation: FloatingActionButtonLocation.endTop,
	),
	),
	),
	);
	expect(tester.getRect(find.byType(FloatingActionButton)), Rect.fromLTWH(16.0, 28.0, 56.0, 56.0));
	});

	testWidgets('Start-top floating action button location RTL', (WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Directionality(
	textDirection: TextDirection.rtl,
	child: Scaffold(
	appBar: AppBar(),
	floatingActionButton: const FloatingActionButton(onPressed: null),
	floatingActionButtonLocation: FloatingActionButtonLocation.startTop,
	),
	),
	),
	);
	expect(tester.getRect(find.byType(FloatingActionButton)), Rect.fromLTWH(800.0 - 56.0 - 16.0, 28.0, 56.0, 56.0));
	});

	testWidgets('End-top floating action button location LTR', (WidgetTester tester) async {
	await tester.pumpWidget(
	MaterialApp(
	home: Scaffold(
	appBar: AppBar(),
	floatingActionButton: const FloatingActionButton(onPressed: null),
	floatingActionButtonLocation: FloatingActionButtonLocation.endTop,
	),
	),
	);
	expect(tester.getRect(find.byType(FloatingActionButton)), Rect.fromLTWH(800.0 - 56.0 - 16.0, 28.0, 56.0, 56.0));
	});
	}


	class _GeometryListener extends StatefulWidget {
	@override
	State createState() => _GeometryListenerState();
	}

	class _GeometryListenerState extends State<_GeometryListener> {
	@override
	Widget build(BuildContext context) {
	return CustomPaint(
	painter: cache
	);
	}

	int numNotifications = 0;
	ValueListenable<ScaffoldGeometry> geometryListenable;
	_GeometryCachePainter cache;

	@override
	void didChangeDependencies() {
	super.didChangeDependencies();
	final ValueListenable<ScaffoldGeometry> newListenable = Scaffold.geometryOf(context);
	if (geometryListenable == newListenable)
	return;

	if (geometryListenable != null)
	geometryListenable.removeListener(onGeometryChanged);

	geometryListenable = newListenable;
	geometryListenable.addListener(onGeometryChanged);
	cache = _GeometryCachePainter(geometryListenable);
	}

	void onGeometryChanged() {
	numNotifications += 1;
	}
	}


	// The Scaffold.geometryOf() value is only available at paint time.
	// To fetch it for the tests we implement this CustomPainter that just
	// caches the ScaffoldGeometry value in its paint method.
	class _GeometryCachePainter extends CustomPainter {
	_GeometryCachePainter(this.geometryListenable) : super(repaint: geometryListenable);

	final ValueListenable<ScaffoldGeometry> geometryListenable;

	ScaffoldGeometry value;
	@override
	void paint(Canvas canvas, Size size) {
	value = geometryListenable.value;
	}

	@override
	bool shouldRepaint(_GeometryCachePainter oldDelegate) {
	return true;
	}
	}

	Widget buildFrame({
	FloatingActionButton fab = const FloatingActionButton(
	onPressed: null,
	child: Text('1'),
	),
	FloatingActionButtonLocation location,
	_GeometryListener listener,
	TextDirection textDirection = TextDirection.ltr,
	EdgeInsets viewInsets = const EdgeInsets.only(bottom: 200.0),
	Widget bab,
	}) {
	return Localizations(
	locale: const Locale('en', 'us'),
	delegates: const <LocalizationsDelegate<dynamic>>[
	DefaultWidgetsLocalizations.delegate,
	DefaultMaterialLocalizations.delegate,
	],
	child: Directionality(
	textDirection: textDirection,
	child: MediaQuery(
	data: MediaQueryData(viewInsets: viewInsets),
	child: Scaffold(
	appBar: AppBar(title: const Text('FabLocation Test')),
	floatingActionButtonLocation: location,
	floatingActionButton: fab,
	bottomNavigationBar: bab,
	body: listener,
	),
	),
	));
	}

	class _StartTopFloatingActionButtonLocation extends FloatingActionButtonLocation {
	const _StartTopFloatingActionButtonLocation();

	@override
	Offset getOffset(ScaffoldPrelayoutGeometry scaffoldGeometry) {
	double fabX;
	assert(scaffoldGeometry.textDirection != null);
	switch (scaffoldGeometry.textDirection) {
	case TextDirection.rtl:
	final double startPadding = kFloatingActionButtonMargin + scaffoldGeometry.minInsets.right;
	fabX = scaffoldGeometry.scaffoldSize.width - scaffoldGeometry.floatingActionButtonSize.width - startPadding;
	break;
	case TextDirection.ltr:
	final double startPadding = kFloatingActionButtonMargin + scaffoldGeometry.minInsets.left;
	fabX = startPadding;
	break;
	}
	final double fabY = scaffoldGeometry.contentTop - (scaffoldGeometry.floatingActionButtonSize.height / 2.0);
	return Offset(fabX, fabY);
	}
	}